Safety drive for motion-picture apparatus



W. WENDERHOLD.

SAFETY DRIVE FOR MoTToN PlcTURE APPARATUS.

APPLICATION FILED APILZB, |917.

Patented Jan. 3, 1922".

2 SHEETS-SHEET I.

u f .rm/enfer W. WENDERHOLD.

SAFETY DRIVE FoR MoTIoN PICTURE APPARATUS.

'APPLICATION FILED APR. 28, 19|?.l 1,402,274.

Patented Jan. 3, 1922.

2 SHEETS-SHEET 2 l /ll Il .Yin/@11501.

WILLIAM .'WENDERHOLD, OF NEW YORK, N. Y., A

PATENT OFFICE.

SSIGNOR T GRU PATENTS CORPO- RATION, A CORPORATION OF NEW YORK.

SAFETY DRIVE FOR MOTION-PICTURE APPARATUS.

Specification of Letters Patent.

Patented Jan. 3, 1922.

Application led April 28, 1917. Serial No. 165,083.

' To all 'whom t may concern.' Be it known that 1, WILLIAM WENDERHOLD,

a citizen of the United States, residing at New York city, in the county and State of New York, have invented certain new and useful improvements in Safety Drives for Motion-Picture Apparatus, of which the following is a clear, full, and exact description.

This ,invention relates to an automatic clutch mechanism for drive shafts in motion picture apparatus and projectors and the like.

The object, is to provide a clutch mechanism controlled by a film band that will disengage the motive power automatically when the lilm has insufficient tension or breaks, .so that all film manipulating parts in such machine cease to operate instantly. The device as disclosed is chiefly designed to disengage automatically. Itis also designed to enablethe operator to re-connect the driving connection clutch' at any time independently, but the duration of said connectlon is always controlled b the automatic disengaging mechanism which is controlled by the film itself.

Referring to the drawings: Fig. l is a partial side elevation of a motion picture apparatus;

ig. 2 is a partial section showing film 4controlled roller and support therefor;

Fig. 3 is a partial section of Fig. 1 showing the throw-out lever;

Fig. 4 is a vertical section of Fig. 1 through the main drive shaft taken on the line 4-4, Fig. 1 and looking in the direction of the arrows;

Fig. 5 is a side elevation of the clutch arm taken on the line 5 5, Fig. 4 and lookin in the direction of the arrows;

Fig. 6 is a section through the clutch arm shaft;

Fig. 7 is a clutch detail showlng one engaging member looking in the directlon of the arrows at 7 7, Flg. 4;

Fig. 8' is a view taken on structure 5. In this structure is also mounted a. yieldable bracket 6 supporting in one end a roller 7 loosely mounted upon shaft 8,

lwhich shaft is extended 'through the bracket -the spring 10 will push the bracket 6 spring 28 becomes very taut and thereby the line 8 8, 20 .Fig 5 and looking in the direction of the 6 to exert pressure upon pawl 9 in 'the upward direction. When the film F leaves the film roller 4, it is passed over the roller 7, thereby pressing bracket 6 downward. When, however, the tension in said film becomes slack, or if the film should break, then upward again. The pawl 9 is mounted on a pivotally mounted lever 11. When members 6 and 8 move upward this lever llis lifted also and drops back again of its own accord, when not otherwise retarded by member 15.

Lever 11 is mounted upon shaft 12 in support 5 carrying at its other end a flXed catch 13, and a spring 14 is mounted upon shaft 12 to give the shaft and the parts thereon mounted a tension sideways. The fixed catch 13 is engaged by the pivotally mounted handle bar 15 upon shaft l16. Shaft 16 is mounted in support 5 and fastened on the upper end of this shaft is the clutch arm 17. The handle bar 15 is fastened to shaft 16 by springs 27 and 28, the clutch arm having two pins 17 a engaging a. groove in the clutch 18, which clutch is slidably mounted upon the main drive shaft 19 but is connected thereto to rotate therewith. The pins 2O engage the hub of the main drive gear 21 loosely mounted on shaft 19. This hub has a series of holes (see Fig. 7).

On shaft 19 is mounted the usual crank arm 22 on one end and a'gear 23 on the other end, which meshes with gear 24 upon axis 25, which carries the drive pulley 26, which is driven by motive power, when crank arm 22 is not employed. It is understood that gear 21 operates the entire apparatus.

The functions of springs 28 and 27 are as follows: When handle bar 15 is forced around shaft 16 by hand till the catch extension 15a has passed the catch 13, the

exerts presure upon clutch arm 17, which will force clutch 18 toward hub of gear 21, and engage the holes therein by means of pins This spring 28 is now highly charged with tension and held that way by catch 13. If, however, the pins 2O are fnot directly opposite the holes in gear hub 21, then the lspring 27 (which is the weaker) will allow the clutch arm 17 to lag behind thevholes meet pins 20. In this way the c hargirg of spring 28 is not interfered with. ow, Shoud the film F allow the arm 6 and its shaft 8 to go upward, touch pawl 9 on lever instantly release the handle bar 15 11, lever 11 and shaft 12 and catch 13 wil an spring 28 being released thereby will instantly disconnect the clutch 18 with great force.

mechanical arrangement, but they are not efficient, owing to the fact thatthe film is not strong enough to operate clutches and even if the film were made stronger, the ilm should not be used for that purpose, as it is too valuable to be used` for mechanical functions. I have therefore designed a clutch which is charged with a spring tension by hand, and very sensitively discharged automatically by the mere absence of iilm This is the chief feature of my invention.`

Vhat I claim' as my invention is: y

1. In a motion picture apparatus, a driving shaft, a clutch thereon, an arm operating said clutch, a spring mounted on said arm, a handle bar operating said arm against the ltension of said` spring, a catch adapted to engage the handle bar, a lever supporting said catch, said lever having a pawl, a shaft engaging said pawl, said shaft carrying a roller, said roller being sup orted by a bracket, said bracket being yielably mounted and said roller being adapted to be iniiuenced by the motion of a' film band adj acent thereto, and a supporting structure for the entire apparatus.

2. In a motion picture apparatus, a driven shaft, a clutch thereon, means for exerting and maintaining a 'tension on said clutch, means for governing said clutch including a pawl and a movable member adapted to enga e said pawl, said member being controlled y a film passing over the same, and menas whereby said member resaid means influence of -the lm is withdrawn.

A3. In a motion picture apparatus the combination of a driving member and aclutch,

v means for exerting tension on said clutch Various devices have been made to accom-v plish this purpose, elther by electrlc'al or and normally tendlng to place said clutch out of engaglng relatlon with said member, means controlled by a film in said apparatus for retaining said clutch in engagement with said driving member, and means actuated by the absence of film in said apparatus for releasilg said retaining means. 4. n an apparatus of the class described, the combination of a driving memberI and a clutch mounted thereon, means for exerting tension on said clutch to normally tend to place the clutch out of engagement with said driving member, a detent for retaining said clutch against tension in engagement with said driving member, means controlled by a film passing through said apparatus for retaining said detent in position and means. for becoming operative by the absence of the `film in said apparatus for releasing said detent.

5. In a motion p'cture apparatus, the combination of a driving member and a clutch, ofmanually o rated means for exerting a tension on sai clutch, and for maintaining said tension on said clutch to normally cause the same to tend to disengage said driving member, means controlled by the presence ofthe film in said apparatus for retaining said clutch in engagement with said driving member and means controlled by the absence of the lm in said apparatus for allowing said clutch to disengage.

/Signed at New York city, New York, thisl 27th day of Aprilone thousand nine hundred and seventeen.

WILLIAM WENDE'RITIOLD. 

